Synthetic versus natural hair makeup brushes:

I always used to pull up my nose when someone mentioned the word "synthetic" in makeup brushes.
In reality, these are great fibers and better than natural hair.
This is explained below:

The process for making Taklon, in which polyester fiber is extruded and tapered to a fine point. It is designed to mimic the handling characteristics of natural sable.
Taklon brushes are more hygienic than real hair brushes. Natural hair has an irregular surface which traps powders, dead skin cells, bacteria and chemicals. Cleaning may not necessarily remove these particles. Because of this, regular cleaning with disinfectants is required to prevent skin irritation. Taklon lacks these surface irregularities, making it easier to clean properly. This decreases irritation. Because Taklon is synthetic, animal cruelty is not an issue.